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1. t nu e h 4 s t e e h s 3 (No Model.) A

- v H. BLACKMAN. PBOGESS 0F AND APPARATUS FR MAKING PAPER PULP.

(No Model.) 3 Sheets- Sheet 2Q H. BLAGKMAN.

PROCESS 0F AND APPARATUS FOB. MAKING PAPER PULP.

,110.530,6351 Patented Den. 11,1894.

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WIT EssEs: @www @ZW By his Attorneys,

(No Model.) 3 SheetsL-.Sheet 3. H. BLACKMAN.

PROCESS OP AND APPARATUS POR MAKING PAPER PULP. NO. 530,635. Pafe'llted Deo. 11,1894.

UNITED STATES PATENT can.

HENRY BLAcKMnN, 'or NEW YORK, N, Y.

P'R'ocsss oF AND AePARATUs/l-I'on MAKING PAPnleuLaf srEcmcn'r'IoN forming pm of zetten Patent No. 530,635, dated lDecember 11, 1.894.

' Application filed ouate 21, issn. nenewea ouate 13.1894. snm n. 52am. (Home.) I

To all whom it may co'ncem.-

, pulp, whether the fibers be preparedy by di-v Be it known that I, HENRY BLACKMAN, a citizen of the United States, residing in New York city, in the county and State of New York, have invented certain new and useful Improvements in Processes of and Apparatus for Makin-g Paper-Pulp, of which the fo1- lowing is a specification.

This invention relates chieiiy `to what is known as the vacuum process of disinte- .grating bers for the manufacture of paper gestion according to the alkali process or the sulphite process. This vacuum process of disintegration is the one described and claimed The invention also relates in part to what is known as the 'sulphurous or sulphite process of disintegrating fibers.

My invention also provides the necessary apparatus for practicingthe improvements in theprocess.. v 1

According to what is known as the sulphurous or sulphite process of making.

paper pulp, vthe wood, straw, or other fibrous matter is exposed in afdigester under considerable pressure and at a high temperature, to the action of asolntion'of sulphurous acid, or preferably of sulphite of soda, potash, lime, or other alkali or base. The boiling is coutinued for several hours, during which ytime by the action of the sulphurous or sulphite solution,- the guinmy or -resinous matters or -other cementing substances that bind the fibers together are decomposed or dissolved,

thereby freeing the pure cellulose which constitutes the essential portion of the fibers, so that at the conclusion of the digesting operation the fibrous matteris discharged as an im pure pulp requiring only washing and beating to fit it'for use. The digester employed consists usually of a steel shell of great Vstrength to withstand the heavy pressure,

and lined with lead to resist the corrosive action of the acid solution.

My present invention, which -in its main features is not limited to the sulphurous or sulphite processes, provides an improved means for disintegrating the tibrous'matter. Accordingtomy said Patent No. 369,836,

.the brous matter was first digested under heat and pressure in a Vsuitable solvent, as/au acid or sulphite solutionor an alkaline soluber4 it wasl washed down' andv pumped out` therefrom and subsequently submitted to washing and scrnbbing'or beating operations to reduce it to the desired grade of pulpiness.

l According to"my present invention I perform the 'blowing oft' or disrupting operation at intervals ,during the digestingr process so that after disruption the fibrous matter is furtherv digested. At each' such disrupting operation the gaseous matter drawn o from the vacuum chamber is immediately or eventually returned to the fibrous matter or solu tion in the digester. .At one or more such disruptions the solution is 'drained off from the iibrousmatter and fresh solution supplied 'to take its placa-after which the brousmat- -teris' pumped back into the digester., .From time to` time during the digesting process the gaseous. matter is drawn off from one 4part of the digester and returned to another `part thereof to cause it to circulate throughthe fibers. At thel end of the digesting operation the fibrous matter is blown out into-the vacuum chamber and continuously pumped back therefrom into the digester, and again' blown out, being thus circulated repeatedly asmany times as is' desirable to produce the requisite Adegree of {ineness of thepulp. AFinally the charge is all accumulated in the j vacuum tion, and pumped out therefrom.

chamber, freed from the gas and spent solu- In order to practicemy present invention,

I provideone or more digesters such as Iare used inthe wellknown sulphite process, and ava'cuuln chamber .or tank to which the di- .gester is connecte'dso that its contents' may lbe blown off into the vacuum chamber, which has a capacity sufficient to receive the entire charge from one digester. I alsogprovide a pu mp for maintaining a'vacuum in this chamber, and between the pump and Avacuum chain- IDO ber I provide a vapor separator and condenser.

These several vessels are connected together through suitable pipes suitably provided with 7.valves for regulating the tlow of gases or liquids therethrough and connected with pumps for circulating the gases or liquids.

In carrying. out my invention I proceed preferably as followsz-I first boil the Wood chips or other fibrous matterfor several hours in an open tank, using simply water, or water in which a considerable portion of soda or other alkali is dissolved. Then when the digester is ready to be charged Itransfer the fibrous matter and liquor to the digester; or the fibrous matter may be placed in the dgester at first without being previously boiled.

The digester being closed, l introduce a suitafford an acid reactions. suitable proportion of sulphurous acid should be forced into render it acid. The liquor or 'solution should cover the fibrous matter. The mass is then boiled in the digester for from twelve to sixteen hours, the necessary heat being applied by injecting steam directly into the solution, or by means of a steamcoil or jacket in th'e bottom of the digester. During the boiling the liquor is circulated through the fibrous matter in any usual way. In the case of a revolving digester this circulation will be effected by turning the digester on its trunnions. In the case of a stationary digester it is effected by pumping the liquor out from the bottom and returning it to the top. From time to time the sulphurous gas is drawn o from the top of the digester and being passed through the condenser is pumped back into the digester at the bottom, thereby, effecting a circulation of the free gas independent of the circulation of liquid. At 'such times the pressure may be reduced and the gas pumped out under a vacuum while Vthe boiling is coutinued. e

During the period of digestion the fibrous matter is disrupted one or more times in accordance with my vacuum process of disintegration described in my aforesaid patent. This disruption is accomplished by blowing off the fibrous matter and liquor from the digester into the vacuum chamber under a consuddenly relieved of pressure is vaporized or converted into steam which tears the bers asunder or disrupts them. The steam, vapor and gas pass out at the top of the vacuum' chamber and are carried through the condenser in which the steam is condensedand passed thence to'the pump. The fibrous matter falls to the bottom of the lvacuum chamber together with the portion of the liquor y which is not vaporized. A During theblowing ot, the disengaged gas is pumpedfrom the vacuum pump back into the top of the digester to assist in maintaining the pressure therein." l

When the entire contents of the digester have been blown off into the vacuum chamber they are returned again to the digester either by pumping them back or by opening valves and turninga pressure of steam into the vacuum chamber sufticient te force them to flow through the communicating pipe {Irorn 11s return or transfer of the fibrous matter and liquor maybe assisted by forming a vacuum in 'the' digester by connecting it with the vacuum pump. This disruption of 4the fibrous matter by,` blowing it off into the vacuum chamberand the subsequent return oimthe fibrous matter to the digester should be practiced several timesduring the period of' digestion. fect'ed as soon as the brous matter is sailici'ently disintegrated by digestion` to enable it to be forced through the contracted nozzle The first disruption should be eff into the vacuum chamber without danger ot' clogging, which will usually be after the digestion has' continued forI about four to six hours. The disruptive operation should be repeated at intervals of three to `four hours duringl the remainder of the digesting operation; At one of the disruptive operations, and preferably after the digestion has/been continued about eight or ten hours the liquor or 'sulphite solution should be' changed. The brousmatter having'all been discharged linto ther vacuum chamber, the pressure in the latter is'restoredto .that of the atmosphere, or to ,above atmospheric pressure, and

`rio.

the old liquor is drained olf from the fibrous matter. Fresh liquor or'sulphite solution is then introduced into the vacuum chamber,

and the -tibrous matter'and, fresh liquor are pumped'orblown back from the vacuum chamber into the digester, whereupon the digestinggprocess is resumed.-

when thedigesnon is completed' the pulp Y is subjected toga final disruptive blowing off into the vacuum chamber. .During this blowing ed it is preferable topunp the pulpand liquor back from the vacuulnchamberinto the digester as fast as it enters, so that. it may be again blown'out and kept in circulation until it has been blown through the contracted IZO nozzle into thevacuum chamber as many v deposited in the vac num chamber the' vacu u rn l is discontinued and the spent liquoris drained off from the pulp. The pulp is then still impregnated to a considerable extent with -sulphurous acid gas, for the removal of which 5 the pulp is heatedwhile under vacu'um.`

This is preferably accomplished by injecting steam into the bottom of the vacuum chamber so that it passes upward through ythe fmass of pulp, the gas thus liberated and the ro steambeing drawn oft by the vacuum. Thus nearly every trace of sulphurous gas is elimi nated from the pulp. Hot water is then-introduced into the topof the vacuum chamber and the pulp is washed` ont tothe pump i 5 which pumps it to theiA usual wash tanks where it `iswashed in the usual manner and is run into .the usual clean pulp chest.v It

may `then be used in anyfknown way for paper manufacture. z c My-p'resent invention comprisingthoseparts -`of. my improved process herein described which pertain to the disruptionofthe fibrous matter by blowing it into the vacuum cham-` g ber, -and to the return. of the,pnlp tothe di.

z5 `gestor to be. again disrupted, may beA pracf ti ced independently of the use of the sulphite process of disintegration, as' for example in' s ing a comparatively shallow ybox or chamber 95 connection with fthe ordinary soda process.

I'will now proceed to describe the new ap- 3c paratus for pulp making invented by me for use in practicing` lthe' process hereinabove specified, referring for thatpurpose to the vaccompanying drawings, wherein- Figure 1 is a generalview of the apparatus 3 5 on a small scale chieiiy in elevation but partly in vertical section. Fig. 2 is' a vertical section on a larger scale of the digester, vacuum chamber, condenser, and their communicating-pipes. Fig..3 is a horizontal section of 4o part of Fig. 1, cut 4on 'the plane of the line 3-3 therein.

' Referring to the drawings, A designates the digester; B, the vacuum chamberC, the condenser; D, the vacuum'fpump; E, the sulphite 45 mixer; `F, the recovery tank;I G, one of the' wash tanks, and H theboiling tank.

l, J, K'and L, are pumps which may be cen'- trifugalpumps.

' shown in my Patents N os. 369,836 and 369,834

of September 13,1887. In the construction1 shown'it consists-ot a. steel-outer shell, with an inner lining of lead as is common in work- 5 '5 ing'under the acid ors'ulphite processes,fwith a largeopening a at .its top through `which to introduce the brous matter and anv outlet a' at its bottom from which leadsa pipe b connecting with a pipe b', extending to the 6o vacuum chamber B, and there-'terminating 1 in a contracted 'nozzle or discharge orifice c.. f In the bottom of the digester is fitted a coni-- The digester'A may be`of'an'yknown--con-, 5o struction, such for example as either of those pipe eleads tothe pump I, anda pipee, leads y i -from this pump to the upper part of the digester which it enters. 'Thus vby operating 7o* thisv pump, .the liquor' may bedrawn down .through the' mass of liber which rests on the screen a, and'retu'rned into the top of the di- A' geste'r, thus instituting a circulation of the liquor through tl;\e'librous matter. The out- 75. l'et a. is closed byna' valve 6 in the discharge pipe b, Steam from the pipel S is admitted f- 'into the top of the digester through a valve '7. f

' If the tank'H is not n sedthe inlet opening a at the top of the digester'is closed by a man- 8o hole plateas shown in Fig. 2. When the tank His employed however, it is arranged preferably directly over the ,digester and communicates-therewith through an outlet .pipe f entering the opening -ctv and closed by a valve'8.' 85

The tank H has a perforated screen or false bottom f', in the space beneath which is a Steam coillf2 into which steam is admittedA throughfthe valvev 9, in order to supply heat for boiling the ibrousmatter in thetank. 9o The vacuum chamber B i`s the samein its general principle' of operation as the vacuum chambers shown:A inmy said Patents Nos..

A369,836 and 869,834,l Instead however of be- -partiallydivided by a pendent partition or target, it is constructed as a: large upright, vessel preferablycylindrical and having va cal Y fpacit suflicient to receivein its lower por- -tion he entire contents of the digester A. roo .The nozzle c enters it at one side near its '.top and directs. the stream' of fibrous matter agai'nst'the target gwhich is'arranged to pro-` jectdown from the topof the chamber. This target has the same' function as the target rc 5 in my Patent 'No.369,836. In the bottom of the chamberis a conical screenor false bottorn' g' -opening downward tothe outlet opening from' a" h governed a :valvflO leads tothe pump L, This pump ds I lo 'charges' into a. pipe h from which there are 'two branches, one of which h2, extends upf -ward and enters the top ofthe digester A, be-J ing governedby ayalve 1l. The other'branch 71.5 leads to. the wash tank G, into which'it dis- 1 x 5 charges, being governed by a valve 12.

From the top of the vacuum chamberB a vapor pipe 'i ,extends upwardly, being prov vided with a yvalve 13, and enters a vapor sep# arator C which consists'of a box or chamber :zo having apendent target or partition tin its upper part 'to deflect downwardly the stream f' of vapors-flowing 'through the chamber ontheir way to the outlet pipe 1?. This outlet pipe leads into the top of the condenser'C, whichmay be'of any construction common forcondensers, and either a surface or j et'cn denser. The condenser shownis a jct'con.- denser. receiving cold water, preferably lime water, from .the pipe W which enters the up- 13o -per pal-tof the condenser andjis perforated to throw jets 'of water thereinto incontact with the steam and vapors, the water thus in -A `troduced being controlled by a valve 15. The

The vacuum'inth" 'cha 'draws the :gases or; vapors out through ,the

fall to 'the bbttom of the condenser and how' od.' by a pipe j leading. to the pump J, while the uncondensed gas and vapors, consisting chietlyof sulphurous gas'and steam, flow out Ywith the suction p ipe k of thevacuum pump densed in this pipekby cold water showered thereinto from a perforated pipe k, fed-by 'a v branch from the pipe W and controlled by a Avalve 16. The lvapor` which' is separated in'` the chamber O -flews down a pipe e", and `is V4discharged *eitherl through a pipe z" into the condenser() or through a pipe i5, back into the vacuumfchatnber-B, its iiow being determined by a tivo-wayV cock-17.- l

lbei' j-B. is .maintained by the operation ofthe pump-D which pipet, separator G', condenser C, ,and pipe 1c,

thel valve 14 being in the position shown. in

` Fig. 2. In order thatY the same pump may also serve for drawing the sulphur gas from 4the top of the digester A, a pipe Z-is provided leading fromthe top ofthedigest-erand coml muncating with the pumpv preferably by joining the pipe i above its valve 13, so that by closing this valve and opening a valve 18 C'; condenser C, and pipe lo. to the pump. l

The gases drawn oir by the pump are discharged through a pipe m in either of three diierent directions, namely: first, through 4a.

'branch pipe m governed by\a valve 19 into the sulphite mixer` E; second, through a branch pipe'fninto a long main pipe pwhich extends from the pump K toa pipe p'fcommunicating' with thedigester or`digestersas will be presently described, theilow through 4the pipe 'It beings governed by a valve 20; third, in casealimetower is used the gas may be dischargedthrough a branch lpipe mgoverned by a valve 2l `and leading to the tower.

The liquid which descends frointthe condenser Gland which will usually be rich in sulphurous gas, is forced by the pump J through the pipej into the sulphite mixer E, this pipe being provided` with a valve. 22.

The sulphite mixer in addition to the inletl pipes m' and j for gas and liquid is provided as shown in Fig. 1 with an inlet lpipe W for admitting lime water,.being governed by a valve 23; and with a pipe M for admitting sulphurous gas from the retort or furnace in which this gas is produced, itsadmission being governed Aby a valve 2,4. In addition the osulphite mixer is provided with an outlet pipe o governed by a. valve 25, and leading to the pump K, by which the snlphite liquor or sol' Y lution prepared in the mixer E is discharged into the digester or Wherever else it is re- 55- quired. l

The liquor .from the sulphite mixer is pump'edby thepumpl through the pipe p and in the pipelthe gases or'vapors may be drawn. throughvthis pipe and through'the separator -K kr or a' fof the digester teem thence either through the pipe which enters tlow into this pipe'being governed by a twoway valve 26, or it-ispumped through the enthe upper part of the vacuum c amber B, the

4tire length'of the pipe. pinto the pipe p' and of the side by a pipe k which leads down and@i thence'into the digeeter either through a pipe communicates through 'the two-way valve 1.4,

pipe is. The pipe r enters ythe bottom beneath the screena, and is controlled by a valve 27.` The pipe s extends :to the top ot the digester, the tlow through it being^ controlled bya valve 28. -Thepipe p. iis furnished with a valve 29 between the :,pump. K and branch pipen, in order to prevent any back iiow`from the pump D through pipee'fn and p toward the pump K.

' Warm or hot water is'su'pplied bya pipeW, 'which has two braiches, one leadingto the boiling 'tank H and controlled bya valve 3 0,

'and the other leadingto the top ofthe vacuum chamber B, and controlled by a valve 3l. i

,"The steam pipe S in addition tofbranches.,

'communicating through vthe valves 9 and`5 s' with the tank H and digester A respectively, has also a branch pipe s" leading to the top of `the vacuum .chamber B and controlled by a valve 32, a branch s2 leading to the bottemof the vacuum chamber beneath the screen g therein and controlled by a valve 33 and abranch .s8 leading to the outlet a. from the digester and controlled by a valve 34. Finally r "the spent liquor is `discharged through the pipe w leading tothe lsewer or elsewhere and governed by valve 87.

The pump D may draw'the sulphurous gas either through the pipe k o r from the tank: li`

through the pipe vor from the retortin which this gas is generatedthrough apipe M, which atter pipe 4comnxunica'tt with its suction chamber, beingcontroll'ed'bya valve 38.

The wash tank'G is of any usual construc-` tion and requires yno desoription..-

Preferably'twd or more digesters A are,4

employed, since with-a single digester the vacuum chamberB, pump D, recovery tank F, te., would be idle the greater part of the time. In Fig. 3, I have shown in horizontal section a vbattery of three digesters A A A, all connected tothe one vacuum chamber B. The outlet pipes hof the three digesters all communicate with a single cross, pipe 112, through which they are put into connection with the pipe b', which extends up to the nozzle c. The single discharge pipe from the pump L enters'a transverse pipe Afrom whichthree vertical pipes h2 ascend and leadto the respective digesters. The single pipe p com municates with atransverse4pipe p' extending under the three digesters, and from which three vertical pipes r r'ascend and enter the f bottoms ofthe digesters, while three pipes s s lbranchlaterally from the pip'e p and extend to the tops of the respective digesters.

The several valves numbered from 5 to 38 may be of any suitable construction, some of these being gate valves, others being globe valves, and others being two-Way cocks.

The general operation of the apparatus will or at the top of the digester. It will usuallyv be introduced at 'the top, in which case the valves 25, 29 and 28 will be opened. I

- In order. to blow 0E the Vfibrous matter into the vacuumchamber to disrupt it, the valve 13 is opened, the .two-way cock 14 is set to the position shown, andthe pumpD is started andoperated until a sujlicient vacuum'is produced in the chamber B. vA sucient pressure being maintained in the vdigester A,- the valve-6 is opened, whereupon by reason of the pressure behind it andthe suction in advance the fibrous mass is forced out and flows in a continuous stream through thenozzle c. into the vacuum chamber. y' Thefibrous matter falls to the bottom of the chamber and may be immediately and continuously pumped back through the pipes h, h' and hby opening the 'valves 10 andll and operating the pump L, whereby the fibrous ,matter will be circulated between the digester and vacuum chamber until it has passed through the ,nozzle as many times as may be desired; or theiibrous matter may, by keeping the valve 10 closed, be permitted to-.accu'mulate in the vacuum chamber. j At each intermediate blowing off or dis- ,ruptive operation, the sulphnrous gases in the vacuutn chamber are pumpedback from the pump. Dv into the digester A through the pipes m n p and s.- Whenever iu the course of a digesting operation itis'found necessary to introduce additional sulphnrous gas into the digester, this is-done by the pump D which draws thegas either from' the pipe- M, or from the recovery tank F through the pipe 'v, and pumps it through pipes m 'n p and (preferably) r into the bottom of the digester..

. To change the liquor after any blowing olf of the pulp, the valve l0 is kept closed and when all the pulp has been blown into the vacuum chamber valve 13 is closed and steam is admitted at 32 to till the vacuum and generate a steam pressure in the chamber B, whereupon the valve 35isopened and-the liquor is forced or runs out through the pipe uinto the recovery tank; Fresh liquor is then supplied from the sulphite mixer through pi pe o, pump K, pipe p, cock 26 and pipe q. f

At the iinal blowing olf-of the pulp into the vacuum chamber the spent liquor is drawn 0E in the same manner, and the sulphnrous gas is then driven 'oi from the pulp'by admitting steam through valve 33, so that it ascends through the mass of pulp, while at the same time. the valve lyibeing opened,.the

-precise succession described.

Vto lhe arts which is capable ot' substitution pump D is operated to ,draw off'th'e sulphurons gas thus expelled. When the sul phurous gas has thusv been sufficiently eliminated, valves 13 and 33 are closed and valves 10 and 3l are opened, so that water enters the -vac-v num chamber and the pulp is washed down into the pump L which v forces it through pipes` h' and ha into one of the wash .tanks G. Whenever during the digestion it is desired to draw off the sulphnrous gas from .the digester, this is done by closing thevalv'e 13,x opening the valve-18 and'operating the pump D, so that the-'gas is drawnot' through the pipe Z. Itmaybe pumped into thesnlphite mixer and its.. place supplied by fresh gas or.

'ISv

it may be pumped back through the plpesl'm, e'

n, p and r into the digester.

If the sulphiteA mixerE be notused, its functions maybe performed. in ameasureby the liquids and gases being? pumped into .the tank E, the liquids will be pumped to the top of the tower and the gasesbe pumped into fthe" usual lime tower, in which case instead of bottom of the tower will be conducted to the pump K which will distribute it through the pipes p, q, lr'- and sin the manner shown. The

,use of the sulphite mixer is preferred how-- ever on accountrof the greater cheapnessand expedition in the recovery ofthe sulphnrous cannot escape tofthe atmosphere and give rise to foul odors.l

gas andbecause the gas is conlined so that it f r vMy improved process may be considerably modified in practice. v'1"hesuccession-of operations which I have herein described is that which Iconsider preferable. Certain of the`se operations however may be omitted and the several steps or operations may be .performed in somewhat different successions than the Although I have referred throughout the specification to the use of a sulphite solution as the reducing liquor, yet -it will be understood that my invention i's applicablein 'con-- nectiou with any solution intowhich sulphurous acidor any other equivalent gaseous solvent or reducing agent enters as a component. Thus the sulphnrous acid may be u sed with water and without any alkali or base.

Itwill-'of course be understood that equivalentd'evices or means may be snbstitutedfor the' .means shown. -For example, the pumps 1, J, K and L, instead of bein centrifugal pumps may be any other kin or construction of pump or any other apparatusknown for.`a pump to yaccomplish the same work. l

For example, a monte-j us 'may be substituted for the pump L; or in any case where a pump vessel to another, the pump may be omitted is used to transfer a liquidY from one closed 'Y entirely and the transfer be'etected' `by es- 'tablishing a dilerence ofpressures between the .two vessels,`theone from which the liquid .is being expelled being given aninternal .Y i

pressure suiiicientlygreater than that in the ro tion with the vessels B and F, the formerbeing. shown arranged on a 'higher level than' the latter, so that the liquid runs olf/itself..

whenever the valve35 is open vand the presslunes in the two vessels are the same or nearly so.' f If the tank F however were arranged on the same level las the' chamber B, orat a higher level, it would be necessary to introduce a pum into the pipe u as' in the case of `the 'pumps and L. ,v vAllof the modifications of apparatus and theirconnections' together shown in 'my said Patents Nos.- 369,834 and 369,836, in sofar as K the same areapplicable in.' connection' with `my.-present invention, are to be construed as 2 5 though their illustration and description were repeated in my present application. For exf ample, the substitution forthe vacuum pump D-as the means for maintaining the vacuum in the vacuum chamber of an ejector as shown 3o in Fig. 5 of` my Patent No. 369,836, may be made and will serve someof the purposes ot'-` my present invention.

i In the foregoing specification I ferred to some .processes and have'described and shown some apparatus'whichare not essential to the practice of the invention claimed herein. This has been done to disclose' the entire apparatus preferably employed in the practice of my present invention, and the re-l 4o lation of the parts claimed to the other parts of the complete apparatus preferablynsed in `connection therewith.

The features thus shown and described which are not essential to my present' inven-l The features of the process and apparatus thus indicated are not claimed hereim/bnt' the essential and novel portions thereof are claimed in my application, Serial N o. 354,7 60, -led J une 9, 18,90, which is a division of my v6e `present application. l v

vIclairn as my invention the several improvements inthe disintegration of fibrous matter for the manufacture of paper pulp and inapparatus therefor defined as follows, eachsub- `6 5 stantiall'y as hereinbefre specified, namely-.-

1. The improved process of preparing paper have rel' pulp, which 'consistsin partially digesting the fibers, 'then disrupting the fibers by blowing them into a vacuum, and then resuming the digestion and repeating the blowing into a vacuum' until the fibers are reduced to the de.

sired fineness. L f l I 2, In an apparatus for disintegrating fiber chamber, an outlet fromthe digester to the vacuum chamber, a vacuum pump for maintaining a vacuum in the-vacuum chamber, and an inletpipe or passage leading from the outlet of. the vacuum chamber to the digester, wherebythe matter blown off from the digester into the vacuum chamber may be returned from the'latter to the digester.

' `3. The combination witha digester having 'an outlet at its. bottom a -vacuum chamber havingan inlet connectedl to said outlpt, ay

*the combination with a digester of a vacuum i.

vacuum pumpfor maintaining a vacuum in said vacuum chamber, a pipe extending from the outletin the lower 'part of the vacuum chamber to the upper part of the digester, and a pump for forcing brous matter through said pipe, whereby the fibrous matter may be drawn by said pump from the vacuum chamber and forced into the digester'during the blowing olf of the fibrous matterfrom the bottom thereof into the vacuum chamber.

2l. The combination of .adigester a discharge outlet at its lower portion, a vacuum chamber having an inlet nozzle or cLifice communicating withpsaid outlet, a. vacuum pump connected to the vacuum chamber to draw loff the gaseous "or vaporous matters therefrom and a -pipe `connecting the discharge of said pump with the digester, whereby during the operation of blowing olif the fibrous matter from the digester into the vacuuml chamber, the gases drawn off by the pump may be reintroduced into thedigester.' 5. The combination with a digester, of a vacuum chamber havingan inlet nozzle or orifice at its upper part communicating with the outlet from the digester, and having a screen or perforated false bottom and a pulp outlet from said screen, a pipe for draining off the liquid from the bottom of the vacuum chamber beneath said screen, and al pipe entering the upper part of the chamber whereby the' fibrous matter discharged into said vacuum chamber may be drained of liquid on said screen and may be supplied with fresh liquid and be discharged through the pulp outlet.

6. The combination with a digester of a vacuum chamber having an inlet nozzle or orifice communicating with the outlet from the digester, a vacuum pump, a pipe connecting the upper part'of the vacuum chamber with the suction of said pump, a steam-pipe entering the lower partyof the vacuum chamber, and a pulp outletle'ading from the lower ,part of said chamber, whereby the fibrous matter may be discharged from the digester into said vacuum chamber, and while under vacuum therein steam may be forced th rough igt ber with the suction of said pump, a valve in said pipe a steam 'pipe entering theupper ro part of the vacuum chamber, and apulp out-l let Vfrom the vlower `part thereoi, whereby when a charge of fibrous matter has been -introduced into the vacuum chamber the latter may be closed at the top and steam pressure t 5 vintroduced thereinto to blow ont the charge from the b'ottom.

8. The combination with a vacuum chamber of a vaporpipe iv ascending from its top,

a vapor separator C -into which said pipe diszo charges and constructed to mechanically disengage particles of liquid fromv the vapor passing through it, a vacuum pump D, and

a pipe connecting` the outlet of saidvapor separatorto the suction of said pump.

9.` The combination with a `vacuum champart thereof, a condenser into which said pipe discharges,

outlet pipe from the upper a liquid outlet from the bottom of saidcondenser, a pump with its suction connected to said liquid outlet to pump away the condens/ed liquid, a gas or vapor .outlet from said condenser, and a vacuum pumpv with its suction connected to said outlet for drawing off the gaseous matter from said condenser and maintaining a; vacuumi in the vacuum chamber.

In witness whereof I have hereunto signed my name in the presence of two .subscribingr witnesses p HENRY BLACKIldAIT-l Witnesses GEORGE H. FRASER, CHARLES K. liRAsER.v 

